Answer: 120 different ways
Explanation:
Assuming you want to arrange the letters of "grade", then we have 5 unique letters. That gives 5! = 5*4*3*2*1 = 120 different permutations. Order matters. The exclamation mark means factorial. It means we start at 5 and count our way down to 1, multiplying along the way.
In other words, we have 5 choices for the first slot, then 4 choices for the next slot, and so on. We count down because we cannot reuse any previously selected letter.
Alternatively, you can use the nPr permutation formula
[tex]_nP_r = \frac{n!}{(n-r)!}[/tex]
where n = 5 and r = 5 since we have 5 letters to pick from and 5 slots to fill.
